In 2004, Waseda University reached another milestone in the development of the anthromorphic flutist robot with the release of the Waseda Flutist No. 4 Refined, more popularly known as the WF-4R. This time, the flute-playing robot was refined with 38 degrees of freedom for its artificial organs.
The artificial lips have five degrees of freedom: three on the upper lip and two on the lower lip. This enables the robot to control the width and thickness of the air beam by controlling the movement of each lip. The lungs, with two piston cylinders, are made to be almost equal to male adult lungs.
WF-4R also has an improved range of motion in its neck. A harmonic drive gear is used for high accuracy positioning. The reduced size and weight of the vibrato mechanism made it possible for installation on the rear of the neck. The small size of the unit is owed to a coiled voice motor.
To improve the range of motion in the arms of WF-4R, the researchers at Waseda University included seven degrees of freedom. The fingers consist of link mechanisms that are actuated by DC servomotors with pulleys and wires.
The musical performance system of WF-4R is composed of two computers, which control the robot’s musical performance. One controls the robot, while the other generates the accompaniment MIDI data. To demonstrate the great flute-playing skills of this humanoid robot, it was made to perform “The Flight of the Bumble Bee”.